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Slim SEO vulnerabilities
Slim SEO has 3 known vulnerabilities in this database. The most recent published record is dated 9 Aug 2026.
- Known vulnerabilities
- 3
- Active installs
- 70,000+
- Latest version
- 4.11.0
- Last updated
- 28 Sep 2026
- Most recent
- 9 Aug 2026
Find it in your WordPress dashboard under Plugins. Severity is based on the CVSS score published with the CVE where one is available.
| Vulnerability | Severity | Affected | Fix | Published |
|---|---|---|---|---|
| Broken access control CVE-2026-16957 | Low 2.7 | Before 4.9.11 | Fixed in 4.9.11 | 9 Aug 2026 |
| Broken access control CVE-2026-12408 | Medium 4.3 | Up to 4.9.8 | Fixed in a later version (latest 4.11.0) | 1 Jul 2026 |
| Cross-site scripting (XSS) CVE-2025-4611 | Medium 6.4 | Up to 4.5.3 | Fixed in a later version (latest 4.11.0) | 21 May 2025 |
Read the published descriptions
- CVE-2026-16957, 9 Aug 2026
- The Slim SEO WordPress plugin before 4.9.11 does not restrict a post-meta preview feature to posts the user is allowed to edit, verifying only read access, allowing users with the Contributor role to read arbitrary post meta, including protected and private keys, of published posts they do not own, including password-protected posts and posts of non-public post types. CVE record
- CVE-2026-12408, 1 Jul 2026
- The Slim SEO - A Fast & Automated SEO Plugin For WordPress plugin for WordPress is vulnerable to Unauthorized Private Content Disclosure in all versions up to, and including, 4.9.8 via the `/wp-json/slim-seo/meta-tags/ai` REST API endpoint. This is due to the endpoint's `permission_callback` performing only a top-level `edit_posts` capability check without verifying that the requesting user has read access to the specific post supplied via the `object.ID` parameter, allowing the `generate` function to pass the attacker-controlled post ID to `Data::get_post_content()`, which calls `get_post()` regardless of post status or ownership. This makes it possible for authenticated attackers with Contributor-level access and above to retrieve AI-generated summaries of the raw `post_content` of arbitrary posts they are not authorized to view - including private posts, drafts, pending, future, and password-protected content authored by other users - with the substance of the protected content disclosed via the HTTP response. CVE record
- CVE-2025-4611, 21 May 2025
- The Slim SEO - Fast & Automated WordPress SEO Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's slim_seo_breadcrumbs shortcode in all versions up to, and including, 4.5.3 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. CVE record
What to do if you run Slim SEO
If you run Slim SEO, open WordPress and check the installed version in Plugins. Compare it with the affected versions in the vulnerability record. If a fixed version is available, take a current backup and update to that version or the latest supported release.
If no fixed version exists, consider disabling and removing the plugin or replacing it with a maintained alternative. After dealing with the affected software, check administrator users, unexpected file changes, redirects, unfamiliar pages and security logs for signs that the site may already have been altered.
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